Lone Atrial Fibrillation Is Associated With Impaired Left Ventricular Energetics That Persists Despite Successful Catheter Ablation
Authors' conclusion
Patients with lone AF have impaired myocardial energetics and subtle LV dysfunction, which do not normalize after ablation.
Study context
- Population
- Patients with symptomatic paroxysmal or persistent lone atrial fibrillation (AF) undergoing catheter ablation
- Participants
- 53 vs 25
- Comparison
- Lone AF patients undergoing ablation vs matched controls in sinus rhythm (SR)
- Lone AFn = 53
- Controlsn = 25reference
- Outcome
- Left ventricular (LV) function and energetics before ablation
- Follow-up
- Before ablation
Methodological detailsmatched controls, MRI for LV ejection fraction (LVEF), peak systolic circumferential strain (PSCS) and left atrial volumes and function; phosphorus-31 MR spectroscopy for phosphocreatine/ATP ratio, AF burden by 7-day Holter before and after ablation; intermittent ECG event monitoring after ablation
- Matched controls
- MRI for LVEF, PSCS and left atrial volumes and function; phosphorus-31 MR spectroscopy for phosphocreatine/ATP ratio
- AF burden by 7-day Holter before and after ablation; intermittent ECG event monitoring after ablation
Main finding
As reported in the abstract
| Group | LVEF (median, IQR) | PSCS (median, IQR) | Phosphocreatine/ATP ratio |
|---|---|---|---|
| Lone AF | 61% [IQR, 52%-65%] | −15% [IQR, −11 to −18%] | 1.81±0.35 |
| Controls | 71% [IQR, 69%-73%] | −18% [IQR, −17% to −19%] | 2.05±0.29 |
LVEF (median, IQR)
Lone AF61% [IQR, 52%-65%]
Controls71% [IQR, 69%-73%]
PSCS (median, IQR)
Lone AF−15% [IQR, −11 to −18%]
Controls−18% [IQR, −17% to −19%]
Phosphocreatine/ATP ratio
Lone AF1.81±0.35
Controls2.05±0.29
- Lone AF vs Controls: P < 0.001 — LVEF
- Lone AF vs Controls: P = 0.002 — PSCS
- Lone AF vs Controls: P = 0.004 — phosphocreatine/ATP ratio
Observational data: associations, not effects.
Further findings
Left atrial size and function before ablation
- Patients had dilated and impaired left atria vs controls
- all P<0.001
LVEF and PSCS change early after ablation, patients recovering SR from AF · 1-4 days
- LVEF change
- 7.0±10%, P=0.005
- PSCS change
- −3.5±4.3%, P=0.001
- Unchanged in those in SR during both assessments
- both P=NS
AF burden · 6 to 9 months after ablation
- Reduced from 54% [IQR, 1.5%-100%] to 0% [IQR 0%-0.1%]
- P < 0.001
LVEF and PSCS after ablation · 6 to 9 months after ablation
- No further improvement
- both P=NS
- LVEF remained impaired vs controls
- P < 0.001
- PSCS remained impaired vs controls
- P = 0.003
Atrial function after ablation · 6 to 9 months after ablation
- No significant improvement from before ablation
- P = NS
- Remained lower than controls
- P < 0.001
Phosphocreatine/ATP ratio after ablation
- Unaffected by heart rhythm during assessment and AF burden before ablation
- both P=NS
- Unchanged after ablation
- P = 0.57
- Lower than controls regardless of recovery of SR
- P = 0.006
- Lower than controls regardless of freedom from recurrent AF
- P = 0.002
Original publication
Lone Atrial Fibrillation Is Associated With Impaired Left Ventricular Energetics That Persists Despite Successful Catheter Ablation. Circulation. Published 14 September 2016. doi:10.
Summarised from the published abstract; every number is checked against it